Structure and floristic composition-environment relationship in a seasonal semideciduous forest, Minas Gerais state, Brazil

Abstract

The aim of this study was to evaluate the structure and floristic diversity in a fragment of Semidecidual Seasonal Forest, in the Sempre-Vivas National Park, Minas Gerais, with the purpose of identifying whether the composition of the species is related to environmental and spatial variables. Thirty plots of 400 m² (20 m × 20 m) were distributed systematically. In each plot, living individuals with diameter at breast height (DBH) were identified and measured ≥ 5.0 cm. Soil samples (depth of 0 - 20 cm) were also collected for further chemical and physical analyses. Classical phytosociological parameters, Shannon diversity index (H') and Pielou equability (J'), diametric distribution and multivariate redundancy analyses (RDA) were calculated. The edaphytic analyses show that this community has clay soil and low availability of macronutrients. On the other hand, the environmental variables (average quota, calcium, manganese, copper, phosphorus and sand) had a significant correlation with the distribution of species (p < 0.05), the environmental and spatial component explained 15% of the species distribution. The unexplained proportion indicates that other variables not measured in this study prevail in the structuring of this community. We found 2,187 individuals, 51 botanical families, divided into: group I with 1017 individuals and 128 species, group II 794 individuals and 132 species and group III 376 individuals and 97 species. The species Licania hoehne and Ocotea corymbosa have the highest values of importance. The diametric distribution shows most individuals focus on the first diametric classes.